In particular in case of locks installed or arranged in moving parts such relative movements between individual parts can generate noise which should generally be avoided for reasons of comfort. Prior art provides several solutions combating this unwanted noise. This is particularly significant for motor vehicles as, during driving, said creaking noises can be generated in particular between the rotary latch and locking bolt. In DE 102 16 313 A1, DE 10 2004 031 266 A1 and DE 10 2006 028 423 A1 the contact points between the rotary latch and locking bolt are provided with a noise damping layer which, at the same time, also aims to reduce wear. DE 10 2004 031 266 A1 describes the arrangement of a spring element or of a spring lip in the lock, also acting on the locking bolt in the closed position. The spring element or the spring lip is preloaded when the locking bolt is inserted. DE 103 20 457 A1 also describes such a spring lip that can be moulded onto the retaining leg for said locking bolt. These known spring lips can also not fully eliminate the creaking noise in the closed position. In DE 2009 032 894.7, not published as yet, the creaking noise has been finally eliminated by the spring lip being equipped with a creaking protection. The suggested creaking protection is a metal plate or profile element slid onto the spring lip.